The present invention relates to an endoscope having means for detecting a shape of an insertion portion when the insertion portion of the endoscope is inserted to a cavity for a pipe path used for an industrial purpose, or such as a cavity of a body canal.
Generally, in an endoscope, a hand-side operation portion is provided at a proximal portion of a slender insertion portion to be inserted into a cavity of a body canal. Further, a curvable portion which is made curvedly deformable is provided at a distal end of the insertion portion. Further, a curving operation portion such as a curvature knob, for operating the curvable portion to curve accordingly, is provided in the operation portion.
In the insertion portion of the endoscope, a distal end structure portion is provided at the distal end of a soft and slender flexible tube portion via the curvable portion. An illumination optical system, an observation optical system and the like are built in the distal end structure portion. In the case where the insertion portion of the endoscope is inserted into the cavity of a body canal, the insertion portion is gradually pushed into the cavity of the body canal by operating the curvable portion to curve to follow the shape of the cavity of the canal. Thus, the insertion portion of the endoscope can be inserted to a deep section of the body canal while deforming the flexible tube section of the endoscope to follow the shape of the body canal. Here, the cavity of a body canal in which the insertion portion of the endoscope is to be inserted, such as that of a large intestine or small intestine, is complicatedly curved around inside. Thus, the shape of the insertion portion of the endoscope inserted in the cavity of the body canal is changed in accordance with the shape of the body canal in which the portion is inserted, and therefore it is not easy for the operator to know the shape of the insertion portion of the endoscope inserted in the deep section of the body canal.
Under these circumstances, for example, Jap. Pat. Appln. KOKAI Publication No. 7-111969 proposes an endoscope which contains an insertion portion shape detection probe for detecting the shape of the insertion portion of the endoscope inserted in the cavity of a body canal. In this document, a core wire is provided in the insertion portion shape detection probe at its axial center portion. Around the core wire, a plurality of coils each for generating a magnetic field are arranged side by side within the insertion portion of the endoscope along its axial direction. These coils are fixed at preset intervals with an adhesive or the like.
To each coil, a signal line is connected. Further, an armor tube is provided around an outer circumference of the shape detection probe so as to protect these coils and signal lines. The endoscope has such a structure that a magnetic field generated from each magnetic field generating coil is detected so as to detect the shape of the insertion portion, and the detected shape of the insertion portion is displayed on a monitor exclusively provided for the purpose.
In the above-described device of the conventional structure, a plurality of coils of the shape detection probe are arranged dispersedly at appropriate locations in the curvable portion of the insertion portion of the endoscope, and in the flexible tube portion. Here, in the case where there are a great number of coils of the shape detection probe, provided in the insertion portion of the endoscope, the accuracy of the detection of the shape of the insertion portion of the endoscope is improved; however, the cost for such a shape detection probe becomes expensive, thus raising the production cost of the entire system of the endoscope device as a problem.
On the contrary, in the case where there are a few number of coils of the shape detection probe, arranged in the insertion portion of the endoscope, the accuracy of the detection of the shape of the insertion portion of the endoscope is deteriorated. Consequently, the shape of the insertion portion of the endoscope cannot be accurately displayed on the monitor. Thus, if the positions of the coils are not proper, the shape of the curvable portion, which changes its shape in a relatively complicated manner, cannot be displayed accurately.
The present invention has been proposed in consideration of the above-described circumferences, and an object thereof is to provide an endoscope device with an improved accuracy of the detection of the shape of the curvable portion, which is capable of reducing the production cost of the entire system.
In order to achieve the above-described object, there is provided according to the present invention, an endoscope device including: an endoscope having a curvable portion capable of changing its shape in a curvable manner, in an insertion potion to be inserted to a cavity of a canal; and
an insertion portion shape detection device for detecting a shape of the insertion portion;
the insertion portion containing an insertion portion shape detection probe in which a plurality of magnetic field generating coils each generating a magnetic field are arranged within the insertion portion along its axial direction,
the insertion portion shape detection device including a detection portion for detecting a shape of the insertion portion by detecting the magnetic field generated from each magnetic field generating coil,
wherein
the shape detection probe includes:
a first coil, provided at neighborhood of a distal end position of the curvable portion, for detecting the distal end position, a second coil, provided at neighborhood of a rear end position of the curvable portion, for detecting the rear end position of the curvable portion, and a third coil at an intermediate position situated between the first coil and the second coil.
In the present invention, while operating the curvable portion to curve, neighborhood of the end positions of both the front and rear portions of the curvable portion are detected with use of the first coil for detecting the distal end position, and the second coil for detecting the rear end position of the curvable portion, and the mid position between both the front and rear end portions of the curvable portion is detected by the third coil situated at the mid position between both the front and rear end portions. As these detected points are connected with a smooth line, the shape of the curvable portion can be detected almost precisely.
Therefore, according to the present invention, all of the coils of the shape detection probe provided in the curvable portion are arranged at neighborhood of the front and end portions of the curvable portion as well as between both the front and rear end portions. With this structure, the accuracy of the detection of the shape of the curvable portion can be improved, and the production cost of the entire system can be reduced.
Further, another object of the present invention is to provide an endoscope device capable of reducing the possibility that the connection portion between the coil end in the shape detection probe and a signal line, or around the end edge of the coil of the armor tube is broken while operating the curvable portion to curve, so as to improve the durability of the shape detection probe.
In order to achieve the above-described object, there is provided according to the present invention, an endoscope device including: an endoscope having a curvable portion capable of changing its shape in a curvable manner, in an insertion potion to be inserted to a cavity of a canal; and
an insertion portion shape detection device for detecting a shape of the insertion portion;
the insertion portion containing an insertion portion shape detection probe in which a plurality of magnetic field generating coils each generating a magnetic field are arranged within the insertion portion along its axial direction,
the insertion portion shape detection device including a detection portion for detecting a shape of the insertion portion by detecting the magnetic field generated from each magnetic field generating coil, the curvable portion having a plurality of curvable regions having different radiuses of curvature from each other, and
the shape detection probe having such an arrangement that the coils are provided in a region of the curvable portion, where the radius of curvature is large.
In the present invention, the curvable portion is operated to curve by bending a plurality of curvable regions of the curvable portion at different radiuses of curvature respectively. Here, with such an arrangement that all of the coils of the shape detection probe provided in the curvable portion are provided in a region where the radius of curvature is large, the tensile force and bending force acting on a connection portion between a coil end of the shape detection probe and a signal line, around an end edge of the coil of the armor tube and the like while operating the curvable portion to curve, are made small.
As described above, according to the present invention, a plurality of curvable regions of different radiuses of curvature from each other, are provided in the curvable portion, and all of the coils of the shape detection probe provided in the curvable portion are provided in a region of the curvable portion, where the radius of curvature is large. Therefore, the breakage of the probe, that is, the connection portion between a coil end of the shape detection probe and a signal line, an end edge of the armor tube and the like, being broken, can be prevented from easily occurring, and therefore the durability of the shape detection probe can be improved.
Furthermore, another object of the present invention is to provide an endoscope device in which the durability of the shape detection probe built in the endoscope can be improved by reducing the possibility of the connection portion between a coil end of the shape detection probe and a signal line, around an end edge of the coil of the armor tube and the like, being broken.
In order to achieve the above-described object, there is provided according to the present invention, an endoscope device including: an endoscope having a curvable portion capable of changing its shape in a curvable manner, in an insertion potion to be inserted to a cavity of a canal; and
an insertion portion shape detection device for detecting a shape of the insertion portion;
the insertion portion containing an insertion portion shape detection probe in which a plurality of magnetic field generating coils each generating a magnetic field are arranged within the insertion portion along its axial direction,
the insertion portion shape detection device including a detection portion for detecting a shape of the insertion portion by detecting the magnetic field generated from each magnetic field generating coil, and
the insertion portion shape detection probe situated at such a position that a moving amount of the insertion portion shape detection probe in an axial direction of the insertion portion becomes minimum.
In the present invention, the moving amount in the axial direction with respect to the curving operation may be small. Therefore, the compression and tension applied on the insertion portion shape detection probe while operating the curvable portion, are reduced. Thus, the durability of the insertion portion shape detection probe is improved, and the durability of the endoscope in which the insertion portion shape detection probe is built, is improved.
Thus, according to the present invention, the insertion portion shape detection probe is arranged at such a position that the moving amount of the insertion portion shape detection probe in the axial direction of the insertion portion becomes minimum, while bending the curvable portion. With this structure, the breakage of the probe, that is, the connection portion between a coil end of the shape detection probe and a signal line, an end edge of the armor tube and the like, being broken, can be prevented from easily occurring, and therefore the durability of the shape detection probe can be improved.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.